Canister Purge Solenoid: Description and Operation

Fig. 101 Upstream Heated Oxygen Sensor Removal/Installation & EVAP Purge Solenoid Location:

PURPOSE
The duty cycle EVAP purge solenoid regulates the rate of vapor flow from the EVAP canister to the throttle body. The PCM operates the solenoid.

OPERATION
During the cold start warm-up period and the hot start time delay, the PCM does not energize the solenoid.
- When de-energized, no vapors are purged.

The engine enters closed loop operation after it reaches a specified temperature and the programmed time delay ends. During closed loop operation, the PCM energizes and de-energizes the solenoid 5 to 10 times per second, depending upon operating conditions. The PCM varies the vapor flow rate by changing solenoid pulse width. Pulse width is the amount of time the solenoid is energized.

The solenoid attaches to a bracket near the front engine mount.

NOTE: To operate correctly, the solenoid must be installed with the electrical connector on top.